We are currently evaluating the viability and cell count of peripheral blood mononuclear cells (PBMCs) subjected to different time lapses under different anticoagulants but same temperature (RT). Time evaluated are 0, 24, 48 and 72 hrs after blood draw into ACD, EDTA and Citrate Vacutainer tubes. We are new at this and have only yet started to get experienced with cell counts and viability estimations using trypan blue. Our preliminary data shows EDTA-stored PBMCs nicely falling in both total cell count and viability...However, Sodium Citrate-Stored PBMCs show a paradoxical increase in cell numbers (although not in viability). Numbers for Citrate-PBMCs start at around 2E6 to 2.5E6 at 0 hrs and hit between 3E6 and 4E6 by 72 hrs! Cells are only subjected to ficoll-1077 isolation immediately after withdrawal (blood withdrawal that is, no sex in our lab, Thank you! ) and are not subjected to any type of stimulation. All procedures are carried out under strict sterile technique (cells are cultured for a week after the procedure to rule out bacterial contamination). Has anyone encountered this ?

I am currently pointing my finger at either: 1) cells being stimulated to proliferate (could this be?) or 2) we are getting better at cell counts, thus the higher cell numbers in the last parts (last 48 hrs that is) of the experiments.

Any suggestions?

-biomol.uaslp-

QUOTE (biomol.uaslp @ May 15 2008, 10:46 PM)

...(blood withdrawal that is, no sex in our lab, Thank you! ) and are not subjected to any type of stimulation.

What kind of dull lab you work in? ..

-cellcounter-

QUOTE (cellcounter @ May 15 2008, 10:54 PM)

QUOTE (biomol.uaslp @ May 15 2008, 10:46 PM)

...(blood withdrawal that is, no sex in our lab, Thank you! ) and are not subjected to any type of stimulation.